How to get a subpoena duces tecum for family court?

I have a custody/visitation/child support pre trial hearing next June. I am pro se. I have started the discovery requests last month. I have sent interrogatories, requests for admissions, and production of documents. The defendant sent me an email stating that he will not comply with my requests and that he will get that letter notarized and mailed to me???So I filed a motion to compel him. The question is, can I subpoena documents from his past employers (for child support)? How can I do that? I just need like his work schedule and his rate of pay, because he cosntantly remains in arrears , but compeletes a financial statement every time showing that he can pay!I also found out that he had a second job. The probation officer asked why he was not paying his child support and he told the PO that he had other things to buy. So anyway.....can I just print the form offline and have it notarized and sent to the employers, or do i have to go to court and filr a motion to get the subpoena's? This is for a pre-trial???Can someone just explain the process to me? I am in MA